Warm air furnace



July 2s, 1942.` AgF. LNAR 2,290,978

WARM'AIR FURNAQE Filed March 14, 1940 3 .Sheets-Sheet 1 [N VENTOR July28, 1942. A, P VAR l 2,290,978

' WARMAIR FURNACE Filed March 14, 1940 3 Sheets-Sheet 2 m [N VEN T 0R BY`FZ-lay:

fm, fag? 25 M A TT ORNE Y v July 1942. *A lP LIVAR A 2,290,978 w-ARMvAIR FURNACE FiledMarch 14, 1940 :s sheets-sheet s f INVENTOR HZZe/f P.WWU M, W

Patented July 28, 1942 WARM AIR FURNACE llen P. Livar, Dayton, Ohio,assigner to Chrysler Corporation, Detroit, Mich., a corporation ofDelaware Application March 14, 1940, Serial No. 323,909

12 Claims.

The present invention pertains to the construction of a warm airfurnace, with particular regard to the provision of means for mountingand aligning the heavy heat exchanging surfaces of the furnace in thejacket of the furnace. The invention is of utmost utility in theconstruction of a gas-red furnace since the nature of the nue gases fromgas flames is such as to make it advisable to use cast iron heatingsections which are less subject to corrosion than Sheet metal heatingsections, although it will be perfectly obvious that other types offuels may be used in a furnace of the present invention and that othermetals than cast iron may be used in the heat exchanging surfaces.

The principal object of the present invention is to devise heatexchanging means of singular efficiency in order that the weight of theheat exchanging means may be reduced to a minimum in spite of the factthat it is made of a heavy metal 'such as cast iron. Another object ofthe present invention is to provide means to support and align a heavyheat exchanger assembly at such a height above the oor as to permit theintroduction of air from a blower means beneath the heat exchangerassembly. Another object of the present invention is to devise the heatexchanger assembly so as to provide the Vsame with a curved bottom wallsuch that the air introduced beneath the heat exchanger assembly will beevenly divided around the bottom of the assembly.

In connection with the provision of means for supporting and aligning aheat exchanger assembly having a curved bottom wall, it is an object ofthe present invention to provide supporting and aligning means whichautomatically align the heat exchanger assembly with the remainder ofthe furnace'so that expensive jigs or iixtures need not be provided forthe purpose of assemblying the furnace. It is an object of the inventionto form such supporting and aligning means so as to be easily assembledwithout the aid of expensive jigs or fixtures for themanufacture of thesupporting and aligningimeans.

It is a further object of the present invention to form the supportingand aligning means as a unitary structure having associated therewithrigid members serving as alignment guides and tip-limiting abutments,between which a portion of the heat exchanger assembly may be placed andinstantaneously aligned in a vertical direcM tion, and which also act toprevent tipping of the heat exchanger assembly beyond a very slightdegree from vertical during the life of the furnace. Y

These and other objects and advantages of the present invention shouldbe readily apparent from the following specification taken in connectionwith the accompanying drawings wherein like numerals refer to like partsthroughout.

In the drawings, Fig.'1 discloses a vertical section through the frontend of the furnace of the present invention, taken substantially alongline l-l of Fig. 2;

Fig. 2 is a vertical section taken at right angles tothe plane of Fig. 1and substantially along line 2 2 of Fig. 1, the figure being on aslightly reduced scale;

Fig. '3 is a vertical section of the rear end of the furnace, takensubstantially along line 3 3 of FigZ; and,

Fig. 4 is a View, substantially similar to Fig. 1, of a modified form offurnace having a plurality of heat exchanger assemblies mounted therein.

Referring to Figs. 1, 2, and 3, there is disclosed a furnace vcomprisingan enclosing jacket 20, and front and rear, vertical partitions 2l and22, respectively, dividing the interior of the furnace into an airentrance compartment 23 at the rear of the furnace, a heat exchangercompartment 24 in the intermediate portion of the furnace, and a frontcompartment 25. Air is admitted to the entrance compartment 23 throughan opening 26 in the top wall of the jacket and drawn through filters21' by blower means 28, mounted in the bottom of the compartment on legs29 provided with resilient feet 30, and driven by a motor 3|. The air isforced into the lower portion of the heat exchanger compartment 24through the blower outlet 35 and between the rear legs 36 and front legs31 of the sup-porting and aligning means 40. The air flows upwardthrough thecompartment 24 in contact 'with the surfaces of the heatexchanger assembly 4l and leaves the furnace jacket through an opening42 in the top wall of the furnace. The openings 26 and 42 are preferablyflanged for connection of the jacket to duct work.

The heat exchanger assembly lll preferably comprises a plurality ofidentical, substantially symmetrical with respect to the vertical centerplane; sections l5 which are provided with complementary internalopenings, forming passages for the gases of combustion, andcomplementary external surfaces, forming passages for the flow of airacross the surfaces heated by the gases of combustion. Each sectionincludes walls 46 rising from a lower rebox portion 47 having a curvedbottom wall 48, In the central upper portion of each wall 45 there isprovided a protruding ange 49, the flanges of adjacent sections forming,together with the sealing rings 50, a gas passage in communication withthe spaces between the walls 48 and the interiors of the rebox portionsand with the interior of a stack con-Y nector 5| extending through thepartition 22, into the compartment 23 and laterally through a side wallof the jacket. rIhe stack connector 5| is fastened to the rear openingof the rear section 45 by tie-rods 52 extending through thecommunicating openings and a cap 53 sealing the front opening of thefront section 45. The re box portions 41 are provided with flangeswhich, together with sealing bands 55, rear plate 56, and iront plate 51form a firebox into whichlthe gas burner 58 or other name-producingmeans is introduced.

The upper portions of the sections 45 are preferably wider than thefirebox portions so as more completely to ll the space between the sidewalls of the jacket, andbafes. extendinginward'from the side walls ofthe jacketidirect the air rising around the lower portions of theassembly into the spaces between the walls 450i adjacent sections. Thewalls 4B arepreferably provided with a plurality ofintegral'heatexchanging pins 6|, preferably arranged in staggered rowsso as to cause the air to follow tortuous courses in contact with thepins and the walls, as shown by full-line arrows. Preferably those ofthe pins in the centralportion of the walls are matched by integralbaffle rods 62 extending between the walls 46 of each section so as tocause the gases of combustion to impart more heat to the walls and pins6|. Also, it is preferable that an arcuate bale 53 extendbetween thewalls 43 substantially in line with the lower parts of flanges 4S so asto cause the flue gases to rise into the upper, outer corners of theheat exchangers beiore travelling horizontally into the stack connector5|, as shown by broken-line arrows.

The plates 56 and 51 are joined by tie-rods 65, 66, 61, and 68, at leasttwo of which, tie-rods 66 and 58, extend horizontally and externally ofthe assembly above the curved bottom walls 48. Mounting bolts -18 and1|, extending forward from plate 51, support a mounting plate 12 whichis sealed to a flange 13 extending forward `from platel 51 throughpartition 2|, and which provides a support for the venturi 15'of the gasburner, the pilot tube 16, an inspection door 11, vand other devicescommonly associated with a gas burner. The tops of each section 45 maybe provided with lug's 8! between which may be placed a humidifier pan8|. vSuitable controls for the furnace (not shown) may be mounted in thecompartment 25 and the jacket may be provided with access doors (notshown) wherever desired.

The heat exchanger assembly is obviously too heavy to be supported bythe partitions 2| and 22 unless such partitions were made of such heavymaterials as to be impractical. Accordingly, the supporting means 48 isVdesigned to carry the entire -weight of the heat exchanger assembly 4|,the heat exchanger assembly being mounted and aligned in the supportingmeans 4|) and the jacket then placed about the combined units. Thejacket preferablyrests upon the floor and preferably has very littlecontact with the heat exchanger assembly so that it may be shiftedslightly after assembly.

The supporting and aligning means 4|) comprises the legs 36 and 31,previously described, lower, horizontal braces 85 connecting the bottomsof legs 35, and connecting the bottoms of legs 31, and upper braces 81and 88 running longitudinally of the assembly between the front and rearlegs and connected thereto by gusset plates 89. The legs extend upwardabove the longitudinal braces 81 and 88, and vertical plates and 9| atthe front and rear, respectively, are welded to the upright extensionsthereof. Each plate is provided with a V-shaped upper edge adapted tocradle a curved bottom wall 48 of `one of the sections 45, with thesides of the V-shaped edges tangentially in contact with the .curvedbottom wall. The angularity of the V is preferably such as to make thepoints of contact "equally spacedhfrom the center plane of the heatexchanger assembly so as to give some lateral support in addition tosupporting the entire weight of theheat exchanger assembly, and so as tocause the heat exchanger assembly to slide into horizontal alignmentwhen rested thereon.

The four legs continue on beyond the curved bottom Ywall and terminate.at such heights with respectY tothe tangential points-of contact of thecurvedzbottom wall and the V-shaped edge of plates.9|l.and :9| as to bebeneath `andf closely adjacent, b'ut'preferably not touching, Ythertie-rods Strand' 68 adjacent'the Vears through which the tie-'rodspass.

This :construction permits theV manufacture of a heat exchanger assemblyhaving `somewhat loose'tolerances and the manufacture of a supportingVstructure and jacket' having equally' loose tolerances. The V-shapededgesof platesv 90 and 9| are cut fairlyaccurately so .thatif the bottomwall of the section were :accurately .machined the heat exchangerassembly wouldalign itself in `,the supporting cradle. However, 'sincecast iron is hardly ever true, .the Arigid,'upper ends of the legs'ofthe .supporting structure'serve as aligninglixtures which .the assemblycrew may observe to '.seethat the heat exchangerfassembly is verticallyaligned. 'No fastening means are necessary foreld assembly since theLheat exchanger assembly isicradled inthe supporting: and aligningstructure, :and the tops ofthe legs prevent serious tipping Vof' theheat :exchanger assembly by abutting thetie-rods inthe event that theheat exchanger'assembly tips toward Vone side or the other.

, Fig. 4 discloses'a .modification/of the present invention' whereinl avplurality of heat exchanger assemblies 4| are cradled side by side in amodied supporting and .aligning structure 40'. In this instance thesupportingand aligning structure comprises a structure includingvertical, front legs 31', vertical, rear legs (not shown) and crossbraces as indicated. 'A modified. vertical plate90 isprovided with aplurality of equal, V-shaped notches in its upper edges adapted tocradle, space, and align theheat exchanger sections. The plate "90' iswelded to vsubstantially vertical, rigid 'members |00 and IDI forming apair of aligningand tip-limiting abutments for one heat exchanger, andrigid members |82 and |83 'forming 'a' second 'pair for the 'other heatexchanger assembly. Plate 90 may be matched by Va similar rear plate(not shown)v and the rigid members maybe matched by a similar rearmember (not shown). It is also preferable that the baiiies 80, mountedon the jacket walls, be supplemented by a central-baule 60 adapted todirect air from the center toward the sides of the compartmentl 24.

It is obvious from inspection of Fig. 1 thatlthe present constructionpermits of limitless alteration in capacity Without material change inthe principal parts. For example, a single heat exchanger section 45 maybe used to form a Very small furnace by mounting plates 56 and 51 onopposite flanges of the section and by attaching stack connector l tothe rear of the single section. Similarly, heat exchanger assembliescomprising any other reasonable number of sections 45 may be built up asshown. In'the case of a single-section heat exchanger assembly it wouldprobably be sufficient to include only the front supporting plate 90 andthe extensions of the front legs 31, or the rear supporting plate 9| andthe extensions of rear legs 36, permitting the opposite end of theassembly to rest upon a simple, supporting member on the frame 40.Similarly, if a greater number of sections were built up to form alonger heat exchanger assembly, a greater number of supporting platesand extensions than, shown might be used in the supporting assembly. Asseen in Fig. 4 a plurality of heat exchanger assemblies may be utilizedso as to limit the length of the furnace to a reasonable limit by usinga plurality of heat exchanger assemblies in side by side relationship ina Wider furnace, in which case it may be preferable so to space thesupporting structure legs as to cause them to serve as braces for theside walls of the jacket.

In the foregoing specification and in the following claims I use theterm cast iron to indicate the preferred material for construction ofthe heat exchanger sections. It is obvious that any material, such asWelded steel plates, may be substituted therefor Without the exercise ofinvention; and the use of the term cast iron is only meant to emphasizethe singular utility of the invention in connection With a heatexchanger assembly of a material having relatively great Weight.

It is also obvious that the present invention could be adapted to theburning of other types of fuels, the disclosure being of agas-iiredfurnace since the use of cast iron or heavy steel plate is particularlyassociated with the use of gas as a fuel. Other types of burner may beassociated with the structure Without the exercise of invention.

Having described preferred embodiments of the invention it should now beapparent to those skilled in the art that the same permits ofmodications in arrangement and detail. All such modications as comewithin the scope of the following claims are considered to be part of myinvention.

I claim:

1. A Warm air furnace comprising a heat exchanger assembly, said heatexchanger assembly being substantially symmetrical vvith respect to avertical, longitudinal plane, and including an externally curved bottomWall substantially symmetrical to said plane, and means to support andalign said heat exchanger assembly in the furnace comprising a frameincluding a vertical plate having a V-shaped notch in its upper edge tocradle the curved bottom wall of vsaid heat exchanger assembly With thesides of the notch contacting said curved bottom wall substantiallytangentially at points equally spaced from said plane.

2. A warm air furnace comprising a heat exchanger assembly, said heatexchanger assembly being substantially symmetrical with respect to avertical, longitudinal plane, and including an externally curved bottomWall substantially symmetrical to said plane, and means to support andalign said heat exchanger assembly in the furnace comprising a frameincluding a plurality of vertical plates each having a V-shaped notch inits upper edge to cradle the curved bottom wall of said heat exchangerassembly With the sides of the notch tangentially contacting said curvedbottom Wall at points equally spaced from said plane.

3. A Warm air furnace comprising a heat exchanger assembly, said heatexchanger assembly being substantially symmetrical with respect to avertical, longitudinal plane, and including an externally curved bottomWall substantially symmetrical to said plane, and means to support andalign said heat exchanger assembly in the furnace comprising a frameincluding a vertical plate having a V-shaped notch in its upper edge tocradle the curved bottom wall of said heat exchanger assembly With thesides of the notch contacting said curved bottom Wall substantialllrtangentially at points equally spaced from said plane, and a pair ofupright, rigid members each extending above a point of contact of saidplate and bottom Wall and terminating adjacent a portion of saidassembly to serve as a vertical alignment fixture and tip-limitingabutment.

4. A Warm air furnace comprising a heat exchanger assembly, said heatexchanger assembly being substantially symmetrical with respect to avertical, longitudinal plane, and including an externally curved bottomWall substantially symmetrical to said plane, and means to support andalign said heat exchanger assembly in the furnace comprising a frameincluding a plurality of vertical plates each having a V-shaped notch inits upper edge to cradle the curved bottom Wall of said heat exchangerassembly with the sides of the notch tangentially contacting said curvedbottom Wall at points equally spaced from said plane, and a plurality ofpairs of upright, rigid members, each pair of members extending abovethe points of contact of one of said plates and the bottom Wallcontiguous thereto and terminating adjacent portions of said assembly toserve as vertical alignment fixtures and tip-limiting abutments.

5. A Warm air furnace comprising a heat exchanger assembly, said heatexchanger assembly being substantially symmetrical With respect to avertical, longitudinal plane, and including an externally curved bottomWall substantially symmetrical to said plane and external abutmentmembers above said curved bottom Wall on each side of the heat exchangerassembly, and means to support and align said heat exchanger assembly inthe furnace comprising a frame including a vertical plate having aV-shaped notch in its upper edge to cradle the curved bottom Wall ofsaid heat exchanger assembly With the sides of the notch contacting saidcurved bottom Wall substantially tangentially at equally spaced lpointsfrom said plane, and a pair of upright,

rigid members each extending above a point of contact of said plate andbottom Wall and terminating closely adjacent and below one of saidabutment members to serve as a vertical align- -ment fixture and tocoact with said abutment "bly being substantially symmetrical withrespect to a vertical, longitudinal plane, and including anexternallycurved bottom wall. substantially symmetrical to said planeand external abutment members above said curved bottom Wall on each sideof theheat exchanger'assembly, and means to support and align said heatexchanger assembly inthe furnace comprising a frame including apluralityof vertical plates each having a V-shaped notch in its upperedge to cradle the curved bottom Wall of said heat exchanger assemblyvvith the sides of the notch contacting saidcurved bottom wallsubstantially tangentially at equally spaced points from said plane, anda plurality of pairs of upright, rigid members, each pair of membersextending above the points of contact of one of said plates and thebottom wall contiguousl thereto and terminating closely adjacent andbelow said abutment members to serve as vertical alignment fixtures andto coact with said abutment members to limit tipping movement of saidheat exchanger assembly.

7. A warm air furnace comprising a heavy heat exchanger assemblyy havingprovision for the transfer of heat from internally combusted fuel to airin contact withftlie external surface thereof and a curvedfbottom walllying on an arc about a point along the vertical centerline of saidassembly, said assembly being of substantially equal proportions on eachside of said vertical centerline so that the center of. gravity thereoflies along said vertical centerline, and means to support and alignsaidheat exchanger assembly in the furnace comprising a frame includinga vertical plate having a V -shaped upper edge adapted to cradle saidcurved bottom wall with the sides of the V-shaped edge tangentiallycontacting said curved bottom wall.

8. A warm air. furnace comprising a heavy heat exchanger assembly havingprovision for the transfer of heat from internally combusted;

fuel to air in contactY with the external surface thereof and aV curved`bottoni wall lying on an arc about a. point along the verticalcenterline of said assembly, .saidassembly'being of substantially equalproportions onleach side of said verticalA centerline so thatY thecenter of gravity4 thereof lies along saidivertical centerline, andmeansto support and align saidY heat exchanger assembly in the furnacecomprising a frame including a plurality'of vertical plates each havingVa V-shaped upper edge adapted to cradle saidcurved bottom wall with thesides of the V-shaped.. edge tangentially contact-ing said curvedbottom; wall.

9. A Warm air furnace comprising a heavy heatexchanger assembly havingprovision for the:

transfer of heat from internally combusted fuelto air in contact'withthe external surface there; of anda curved bottom wall lying on an arcabout` a point along the Vertical centerline of said assembly, saidassembly being of substantially equal`- proportions on each side of saidvertical centerline so that the center of gravity thereof lies along,said vertical centerline, and means to support andv align said heatexchanger assembly in the furnace comprising a frame including avertical plate having a V-shaped upper edge adapted to cradle saidcurved bottom wall with the sides of the V. shaped edge tangentiallycontacting said curved, bottom Wall, and a pair of upright, rigidmembers each extending above a point of contact of said.

plate and bottom wall and terminating adjacent a portion ofv saidassembly to serve as a verticalV alignment fixture and tip-limitingabutment.

l0, A warm air furnace comprising a heavy heat exchanger assembly havingprovision for the transfer of` heat from internally combusted fuel toair in contact with the external surface thereof and a curved bottomwall lying on an arc about a point along the vertical centerline of saidassembly, said assembly being of substantially equal proportions on eachside of said vertical centerline so that the center of gravity thereoflies along said vertical centerline, and means to support and align saidheat exchanger assembly in the furnace comprising a frame including aplurality of vertical plates each having a` V-shaped upper edge adaptedto cradle said curved bottom wall with the sides of the V-shaped edgetangentially contacting said curved bottom wall, anda plurality of pairsof upright, rigid members, each pair of members extending above thepoints of contact of one of said plates and the bottom wall contiguousthereto and terminating# adjacent portionsV of said assembly to serveasvertical alignment fixtures and tip-limiting abutments.

l1. A warm air furnace comprising a heavy heat exchanger assembly havingprovision for the-*transfer of heat from internally combusted fuel toair in contact with the external surface thereof and a curved bottomWall lying on an arc about a point along the vertical centerline of saidassembly, said assembly'being of substantially equal proportions on eachside of said vertical centerline so that the center of gravity thereoflies along said vertical centerline, a horizontally extending tie-rod ateach side of said heat exchanger and externally thereof, and meansto-support and align said heat exchanger 'assemblylin the furnacecomprising a frame including aV vertical plate having a `Vshaped upperedge adapted to cradle said curved bottom wall with thesides of theV-shaped edge tangentially contacting said curved bottom wall, and apair of upright, rigid members each extendingv above a point' of contactof said plateV and bottom Wall and terminatingclosely adjacent and belowone of? said tie-rods to serve' as a vertical alignment fixture and tocoact with said tie-rod to limit tipping movement of said'heat exchangerassembly.

12. A warm air furnace comprising a heavy heat exchanger assembly havingprovision for the transfer of heat from internally combusted fuel to airin Ycontact with the external surface thereof and a curved bottomwall-lying on an arc about affpoint along the vertical centerline ofysaid assembly, said assembly being of substantially equal proportions oneach side of said vertical centerline so that the center of gravitythereof lies along said vertical centerline, a horizontally extendingtie-rod at each side of said heat exchanger and externally thereof, andmeans to support and align said heat exchanger assembly in the furnacecomprising a frame including a plurality of vertical plates each havinga Vshaped upper edge adapted to cradle said curved bottom wall with thesides of the V-shaped edge tangentially contacting said curved bottomwall and a plu-4 rality of pairsof upright, rigid members, each pair, ofmembers extending above the points of contact of one of said plates andthe bottom wall contiguous thereto and terminating closely. adjacent andbelow said tie-rods to serve as vertical alignment fixtures and to coactwith said tierods to limit tipping movement of said heat exchangerassembly.

- ALLENY P. LIVAR.

